The invention relates to lining material for footwear and particularly to a multilayered material usable for the insole of footwear. Such a material should be dense enough to provide support for the foot, resilent enough to cushion the impact of the foot on the ground, absorbent enough to soak up perspiration and durable enough to provide long service. These qualities are particularly important in footwear which is intended to be utilized primarily in sports activities.
The resiliency may be provided by a layer of polyether foam or polyurethane foam but these materials lack the requisite absorbency. The addition of a layer of fabric such as cotton drill, on the foam layer will provide absorbency but polyether foam or polyurethane foam are not dense enough to provide the necessary support for footwear insoles.
Reprocessed polyether foam or polyurethane foam includes a number of flakes of recycled or reconstituted polyether, polyurethane or both bonded into a solid resilient mass within a polyether linking agent or a polyurethane linking agent. If such reprocessed foam is used rather than virgin polyether foam or polyurethane foam material the resulting foam layer will have increased density and will provide adequate support and resiliency. Reprocessed foam is also less costly than virgin material making the resulting liner material less expensive to manufacture. It has been found, however, that reprocessed foam material has two undesirable features which make it unsuitable for use in this application. First, the hard flakes of recycled material included within the reprocessed foam would create discomfort and would provide a source of possible irritation to the wearer's foot, if used in lining material for shoes. Secondly, the reprocessed foam may include material which is not flame laminable so that it could not be attached to cotton drill by the flame lamination technique which would be most advantageous for this purpose.
In order to overcome these difficulties and provide a superior material for lining footwear utilizing inexpensive reprocessed foam, applicant provides a novel layered material as described more fully below.